package com.yiwenup.leetcode.top_interview_150;

/**
 * 文件描述
 *
 * @Project struct-algorithm
 * @Package com.yiwenup.leetcode.top_interview_150
 * @Author yiwenup
 * @Date 2024-12-05 17:52:05
 * @Description https://leetcode.cn/problems/rotate-array/?envType=study-plan-v2&envId=top-interview-150
 * <pre>
 *     给定一个整数数组 nums，将数组中的元素向右轮转 k 个位置，其中 k 是非负数。
 * </pre>
 * <pre>
 *     输入: nums = [1,2,3,4,5,6,7], k = 3
 *     输出: [5,6,7,1,2,3,4]
 *     解释:
 *     向右轮转 1 步: [7,1,2,3,4,5,6]
 *     向右轮转 2 步: [6,7,1,2,3,4,5]
 *     向右轮转 3 步: [5,6,7,1,2,3,4]
 * </pre>
 * <pre>
 *     输入：nums = [-1,-100,3,99], k = 2
 *     输出：[3,99,-1,-100]
 *     解释:
 *     向右轮转 1 步: [99,-1,-100,3]
 *     向右轮转 2 步: [3,99,-1,-100]
 * </pre>
 */
public class No0189 {
    public void rotate(int[] nums, int k) {
        k %= nums.length;
        if (k == 0) {
            return;
        }
        reverse(nums, 0, nums.length - 1);
        reverse(nums, 0, k - 1);
        reverse(nums, k, nums.length - 1);
    }

    public void reverse(int[] nums, int start, int end) {
        while (start < end) {
            int temp = nums[start];
            nums[start] = nums[end];
            nums[end] = temp;
            start += 1;
            end -= 1;
        }
    }
}
